BackgroundPatients with recurrent glioblastoma (rGB) have a poor prognosis with a median overall survival (OS) of 30–39 weeks in prospective clinical trials. Intravenous administration of programmed cell death protein 1 and cytotoxic T-lymphocyte-associated antigen 4 inhibitors has low activity in patients with rGB. In this phase I clinical trial, intracerebral (IC) administration of ipilimumab (IPI) and nivolumab (NIVO) in combination with intravenous administration of NIVO was investigated.MethodsWithin 24 hours following the intravenous administration of a fixed dose (10 mg) of NIVO, patients underwent a maximal safe resection, followed by injection of IPI (10 mg; cohort-1), or IPI (5 mg) plus NIVO (10 mg; cohort-2) in the brain tissue lining the resection cavity. Intravenous administration of NIVO (10 mg) was repeated every 2 weeks (max. five administrations). Next generation sequencing and RNA gene expression profiling was performed on resected tumor tissue.ResultsTwenty-seven patients were enrolled (cohort-1: n=3; cohort-2: n=24). All patients underwent maximal safe resection and planned IC administrations and preoperative NIVO. Thirteen patients (cohort-1: n=3; cohort-2: n=10) received all five postoperative intravenous doses of NIVO. In cohort-2, 14 patients received a median of 3 (range 1–4) intravenous doses. Subacute postoperative neurological deterioration (n=2) was reversible on steroid treatment; no other central nervous system toxicity was observed. Immune-related adverse events were infrequent and mild. GB recurrence was diagnosed in 26 patients (median progression-free survival (PFS) is 11.7 weeks (range 2–152)); 21 patients have died due to progression. Median OS is 38 weeks (95% CI: 27 to 49) with a 6-month, 1-year, and 2-year OS-rate of, respectively, 74.1% (95% CI: 57 to 90), 40.7% (95% CI: 22 to 59), and 27% (95% CI: 9 to 44). OS compares favorable against a historical cohort (descriptive Log-Rank p>0.003). No significant difference was found with respect to PFS (descriptive Log-Rank test p>0.05). A higher tumor mRNA expression level of B7-H3 was associated with a significantly worse survival (multivariate Cox logistic regression, p>0.029).ConclusionIC administration of NIVO and IPI following maximal safe resection of rGB was feasible, safe, and associated with encouraging OS.Trial registrationNCT03233152.

Intratumoral (IT) myeloid dendritic cells (myDCs) play a pivotal role in re-licensing antitumor cytotoxic T lymphocytes. IT injection of the IgG1 monoclonal antibodies ipilimumab and avelumab may induce antibody-dependent cellular cytotoxicity, thereby enhancing the release of tumor antigens that can be captured and processed by CD1c (BDCA-1)+ myDCs. Patients with advanced solid tumors after standard care were eligible for IT injections of ≥1 lesion with ipilimumab (10 mg) and avelumab (40 mg) and intravenous (IV) nivolumab (10 mg) on day 1, followed by IT injection of autologous CD1c (BDCA-1)+ myDCs on day 2. IT/IV administration of ipilimumab, avelumab, and nivolumab was repeated bi-weekly. Primary objectives were safety and feasibility. Nine patients were treated with a median of 21 × 106 CD1c (BDCA-1)+ myDCs, and a median of 4 IT/IV administrations of ipilimumab, avelumab, and nivolumab. The treatment was safe with mainly injection-site reactions, but also immune-related pneumonitis (n = 2), colitis (n = 1), and bullous pemphigoid (n = 1). The best response was a durable partial response in a patient with stage IV melanoma who previously progressed on checkpoint inhibitors. Our combinatorial therapeutic approach, including IT injection of CD1c (BDCA-1)+ myDCs, is feasible and safe, and it resulted in encouraging signs of antitumor activity in patients with advanced solid tumors.

Background Intratumoral (IT) myeloid dendritic cells (myDCs) play a pivotal role in initiating antitumor immune responses and relicensing of anti-tumor cytotoxic T lymphocytes within the tumor microenvironment. Talimogene laherparepvec (T-VEC) induces immunogenic cell death, thereby providing maturation signals and enhancing the release of tumor antigens that can be captured and processed by CD1c (BDCA-1) + / CD141 (BDCA-3) + myDCs, in order to reinvigorate the cancer-immunity cycle. Methods In this phase I trial, patients with advanced melanoma who failed standard therapy were eligible for IT injections of ≥1 non-visceral metastases with T-VEC on day 1 followed by IT injection of CD1c (BDCA-1) + myDCs +/- CD141 (BDCA-3) + myDCs on day 2. T-VEC injections were repeated on day 21 and every 14 days thereafter. The number of IT administered CD1c (BDCA-1) + myDCs was escalated from 0.5×10 6 , to 1×10 6 , to a maximum of 10×10 6 cells in three sequential cohorts. In cohort 4, all isolated CD1c (BDCA-1) + / CD141 (BDCA-3) + myDCs were used for IT injection. Primary objectives were safety and feasibility. Repetitive biopsies of treated lesions were performed. Results In total, 13 patients were enrolled (cohort 1 n=2; cohort 2 n=2; cohort 3 n=3; cohort 4 n=6). Patients received a median of 6 (range 3–8) T-VEC injections. The treatment was safe with most frequent adverse events being fatigue (n=11 (85%)), fever (n=8 (62%)), and chills/influenza-like symptoms (n=6 (46%)). Nine (69%) and four patients (31%), respectively, experienced pain or redness at the injection-site. Clinical responses were documented in injected and non-injected lesions. Two patients (cohort 3) who previously progressed on anti-PD-1 therapy (and one patient also on anti-CTLA-4 therapy) developed a durable, pathologically confirmed complete response that is ongoing at 33 and 35 months following initiation of study treatment. One additional patient treated (cohort 4) had an unconfirmed partial response as best response; two additional patients had a mixed response (with durable complete responses of some injected and non-injected lesions). On-treatment biopsies revealed a strong infiltration by inflammatory cells in regressing lesions. Conclusions IT coinjection of autologous CD1c (BDCA-1) + +/- CD141 (BDCA-3) + myDCs with T-VEC is feasible, tolerable and resulted in encouraging early signs of antitumor activity in immune checkpoint inhibitor-refractory melanoma patients. Trial registration number NCT03747744 .